DESCRIPTION: (verbatim from the application) Today, the increased longevity and mobility of individuals with spinal cord injury (SCI) has led to disabling shoulder pain becoming a significant clinical problem which has been related to the demands of wheelchair propulsion (WCP). The goal of this project will be to develop guidelines for the reduction of the demands on the shoulder during WCP for persons with SCI. Specifically, the aims are to determine the effects of changes in the horizontal wheelchair seat position and a muscle strengthening exercise intervention on the shoulder joint forces and muscle activity during WCP in persons with paraplegia and tetraplegia from complete SCI. Subjects with SCI who are asymptomatic for shoulder joint pain and those who report shoulder pain during WCP will be tested. Participants will be grouped according to SCI level of injury (paraplegia, C7 tetraplegia and C6 tetraplegia). Subjects will wheel their chairs, on a wheelchair ergometer in three horizontal seat positions at free and fast velocities and on a simulated 8 percent incline. Subjects will maintain fixed velocities in the three seat positions for each propulsion condition. Function of the supraspinatus, infraspinatus, sbscapularis, anterior and middle deltoid, serratus anterior, sternal pectoralis major, middle and lower rapezius and rhomboid major will be recorded with dynamic EMG using intramuscular fine wire electrodes. Motion of the shoulder, elbow and wrist joints will be measured with the Vicon Motion Analysis System. WCP forces will be recorded with a strain gauge instrumented wheel. Maximal isometric shoulder elevation in the sagittal and scapular planes (scaption), shoulder adduction and internal and external rotation torques will be measured with a LIDO dynamometer. A sub&#8209;group of the subjects will participate in a 12 week shoulder muscle strengthening and flexibility exercise program. Those subjects who do not participate in the exercise program will serve as a control group. Both exercise and control subjects will return every three weeks for strength assessment. The strength and propulsion tests will be repeated for all subjects at the end of the 12 week period. The data will be analyzed to compare the shoulder joint forces, moments, patterns of muscle activity and reports of shoulder pain during WCP in the three seat positions and before and after the exercise program. Statistical significance of the findings will be determined by repeated measures MANOVA analyses with grouping factors for SCI level and exercise/control groups.